Treatment of filamentary materials



D 3, 1935. E. L. GREENWOOD 2,022,854

TREATMENT OF FILAMENTARY MATERIALS Filed Feb. 27, 1933 is o o o Patented Dec. 3, 1 935 TREATMENT OF WAR-Y IATERIALS EmestLeslieGmenIoolLSponflomnear assignortocelanese England,

Derby, of

America, a corporation of Delaware Application February 21, 1933, Serial No. 658,715

In Great Britain March 7. 1932 9 Claims. (CI. 9138) e This invention relates to the treatment of filamentary materials such as yarns, threads, straws, tapes, bristles, ribbons and like textile materials (hereinafter referred to as yams) and is particularly concerned with the application of liquid materials such as dyes, sizes or conditioning liquids to the surfaces of said yarns while they are travelling.

In the application of liquids to travelling yarns, wicks may be used over and in contact with which the yarns are caused to run, the lower ends of the wicks dipping into 'a'vesselcon ni the liquid to be applied so that the liquid isconveyed to the filaments along the wick by .capillary action. It is found however, that where'the con tact of the filaments with the liquid contained in the wick has the effect of altering the nature of the liquid remaining in the wick, even to a slight degree, difliculties arise on account of the lack of uniformity of the nature of the liquid applied. For example, where as is frequently the case with artificial yarns, a solvent liquid is applied to the yarns, the substance of the yarns becomes dissolved to a slight degree in the liquid remaining in the wick, with the result that the nature of the liquid subsequently applied to the yarns varies. Or again, where a mixture of liquids is applied one of which has a particular aflinity for the substance of the yarns, e. g. in the case of some dyestuits, the proportion of the liquid having such aflinity is reduced in the liquid remaining in the wick, so that the applied liquid is not uniform in nature. The exhausted liquid present in the wick prevents fresh liquid from being supplied to the filaments, and renders it necessary periodically to change the wicks. This step however does not remedy the lack of uniformity in the liquid applied, and gives rise to periodic variations in the yarn ultimately produced. It is an object of the present invention to provide means whereby uniformity of the nature of the liquid applied to the travelling yarns is maintained.

According to the present invention, apparatus for the application of liquid material to travelling yarns comprises a wick, and means for causing the liquid to be applied to flow continually through such wick. In this manner the liquid presented to the yarns is continuously renewed so that an alteration in the nature of the liquid which has already been presented to the yarns is immaterial, since subsequently afresh and renewed body of liquid is presented. As a result the action of the applied liquid upon the yarns is action of the wick itself.

'be of constant level in order to ensure uniformity of flow. The longer limb of the wick may allow the liquid to drip into a receiver, or it may be arranged to dip below the surface, preferably at constant level, of the liquid in the receiver. In this manner a very uniform rate of ilow of liquid through the wick is obtained and the uniformity of the nature of the liquid applied to the yarn is ensured. Other methods of renewing the liquid in the wick may be adopted. For example, the liquid may be caused to drip steadily on the wick and to soak by capillary action past the point over which the filaments are running, leaving the wick by flowing along a downwardly extending limb hanging into a receiving vessel or into the liquid contained in such vessel.

The applied liquid may be circulated repeatedly through the wick, or if desired may be used once only and then discarded. Where the alteration in the nature of the liquid is not very considerable, the method of circulation is generally preferable. The composition and nature of the whole bulk of liquid in circulation may in such circumstances be allowed to vary within narrow the variations being however far less than would take place in a liquid normally applied by means of an ordinary wick, since the variation is distributed throughout the bulk of liquid in circulation instead of being confined to that portion of the liquid contained in the wick. Where such slight variations in the applied liquid are not permissible, steps may be taken to restore the original quantities of liquid which has passed through the wick to the receiving vessel before recirculation. Thus for example, in making up the bulk of the liquid in circulation to allow for the liquid which has been applied to the yarn, the composition of the added liquid may differ considerably from that of the liquid to be applied, in order to produce throughout the bulk of the liquid the change necessary to restore the liquid to its original state. This method may be employed even when the change in the nature of the liquid taking place during the application of such liquid to the yarns is quite considerable, e. g. in

the application of a-dyestufi having an aiilnity for the yarn and applied in a liquid vehicle.

Instead of using a single wick in which case the yarn is preferably caused to run over the highest point of the wick, such a device as is described in U. S. application S. No. 538,484 filed May 19, 1931 may be used, where two wicks hanging over horizontal bars are pressed together upon a yarn passing between them. Each wick may be arranged as a siphon in the manner described above, or alternatively the liquid to be applied may be caused to drip on the top points of the two wicks and allowed to run down past the point of contact with the filaments, and to fiow from the ends of the two wicks into one or more receiving vessels.

The invention is suitable generally for the application of liquids to filamentary materials, and

is particularly suitable in connection with artificial textile materials made of or containing artificial filaments, straws, tapes, bristles or the like. Thus for example, the invention may be employed in connection with yarns consisting of filaments of reconstituted cellulose, such as cuprammonium or viscose silk, or of filaments of organic derivatives of cellulose. Examples of organic derivatives of cellulose are cellulose esters such as cellulose acetate, cellulose formate, cellulose propionate and cellulose butyrate, and cellulose ethers such as ethyl and benzyl cellulose. Further, the invention may be applied to yarns of natural or artificial staple fibres, such as yarns of silk, cotton, wool, artificial staple fibres or mixtures of these materials, or indeed to any other materials in the form of a filament or a bundle of filaments.

Furthermore, the invention is especially applicable to the treatment of artificial filaments, and especially artificial filaments of cellulose acetate or other organic derivatives of cellulose, continuously with their production, e. 'g. by the dry or evaporative method. Such materials however, as well as yarns of natural fibres such as silk, cotton, wool or the like or mixed yarns, may

be treated otherwise than continuously with their production, as for example, during bobbin-tobobbin or other winding operations.

The invention may be used to apply any desired liquid to the yarn, but is particularly suitable for the application of a relatively thin liquid such as may be ordinarily applied by means of a wick. The considerable advantages of the invention arise, however, when a liquid or a mixture of liquids is used whose nature is altered by contact with the filaments. Thus, the invention may advantageously be employed in the application to the yarn of suspensions or dispersions of solids in liquids, or in the application to the yarn of liquids having a solvent action upon the yarn itself. By means of the device of the present invention, the wick is constantly flushed and washed through with the liquid flowing along it, and the disadvantages of clogging of the wick, or of cumulative contamination of the applied liquid, are prevented.

In connection with the application of solvent liquids mentioned above, the invention is particularly applicable in the production of unitary filaments such as horsehair, tapes, ribbons or straws from a. number of artificial filaments, especially from filaments of organic derivatives of cellulose. In the manufacture of products 0! the kind referred to, a liquid may be applied to the individual filaments which has a solvent or softening action thereon, after which they are caused to adhere to one another. It is of great importance that the solvent liquid should be applied to the individual filaments with the greatest degree of uniformity. Thus for example, if the liquid being applied becomes charged with the substance of 5 which the filaments consist, the solvent action is reduced, while at the same time undue and irregular brightness and lustre is produced in the finished product. On the other hand if the liquid is applied in such quantity as to obviate this difil- 10 culty the filaments, upon initial application of the solvent, are unnecessarily and irregularly softened with unsatisfactory results, e. g. in the production of a flattened product variations in width of the product. By the employment of the 15 liquid applying means of the present invention, these disadvantages are removed and uniformity of application in respect of the nature of liquid applied is ensured. In this instance it is preferable in order to obtain uniformity in the quango tity of liquid applied, to make use of wicks described in U. S. application S. No. 538,484 in combination with the present invention in the manner previously described. It may be found advantageous in this connection, particularly if 25 the pure solvent is so thin and fiuid as to flow more freely than is desired, to employ a solvent containing a small proportion say 0.1% of the substance of which the filaments consist, the advantages of this step being rendered possible by 30,

the fact that uniformity of the application is en sured by the means according to the invention, so that the larger quantities of the material of the filaments are not dissolved in the liquid in the course of the application.

The invention is not of course confined tothe use of one moistening device. Two or more devices supplying the liquid may be used on the same yarn, or one or more of the devices according to the invention may be used in conjunction with moistening devices of any other-character for the purpose of applying one or more liquids to a travelling yarn.

The invention will now be described in greater detail with reference to the acompanying draw- 45 ing, but it is to be understood that this description is given by way of example only and is in no respect limitative.

Figure 1 shows a form of apparatus for the production of ribbons from filaments of organic 5 derivatives of cellulose, and

Figure 2 is a sectional view of a liquid applying device employed in the apparatus shown in Figure 1.

A number of threads 4 each consisting of con- 55 tinuous filaments of cellulose acetate or other organic derivative of cellulose are drawn from bobbins 5 mounted in a creel 6. The threads 4 are passed through a. spacing reed 1 and over and under a pair of rods 8 so that they are formed 50 into a ribbon 9. The ribbon 9 is passed over a liquid applying device In by means of which a solvent for the substance of the filaments is applied to them and they are then drawn at a sharp angle round two knife edges II and I2, and round a 05 roller I3 which serves to draw them through the apparatus. From the roller l3 the ribbon 9 proceeds through a pair of nipping rollers IS, the combined action of the knife edges I I and I2 and the nipping rollers 15 causing the filaments pre- 70 viously softened by the solvent applied from the device ill to unite together to form a unitary product of flattened cross section. This ribbonlike product is wound on a bobbin l6 driven by means of a drum i1 at constant peripheral speed 1 so that the rate of collection of the product is uniform.

In the device III a wick H by means of which a solvent liquid is applied to the ribbon 9 dips into a reservoir 20 containing the liquid to be applied. The reservoir 20 is supplied with liquid through a funnel 2|, the liquid being maintained at a constant level, excess liquid draining away through a small hole 22 in one wall of the vessel. The liquid supplied may be a pure solvent for the substance of the filaments, or it may contain in solution a small quantity of the derivative of cellose of which the filaments consist.

The wick l9 dips at one end into the liquid in the reservoir 20 and hangs over an extension 23 of the wall of the reservoir 20 into an outside chamber 24, the free end 25 of the wick l9 hanging considerably below the level of the liquid in the reservoir 20. The liquid which runs through the hole 22 in the reservoir 20 and that which drips steadily from the free end 25 of the wick I9 collects in the chamber 24 and is drawn away at intervals by a cock 26. A cover 21 is provided for the device, the wick I 9 being covered by a dome 28 which is cut away at 29 for the passage of the filaments 9 over and in contact with the wick as shown at 30. The cover 21 and dome 28 almost entirely close the liquid applying means, and so minimize' losses of solvent material by evaporation.

The liquid drawn away by the cock 26 may be returned to the reservoir 20, either directly, or after regeneration to bring it to the same state as the liquid contained in the reservoir. Thus, if a weak solution of cellulose derivative is employed, and if in its passage through the wick, such solution dissolves a further amount of cellulose derivative from the filaments 9, the liquiddrawn from the cock 26'may be restored to the desired concentration by the addition of the requisite quantity of pure solvent.

What I claim and desire to secure by Letters Patent is:--

1. Method of maintaining uniformity in the nature of a liquid to be applied to a travelling yarn by means of a wick, which comprises running the yarn in contact with the wick at a point along the length of the wick, causing the liquid which is to be applied to flow by. capillary action continually throughthe wick, and to and down past the point of contact of the travelling yarn therewith.

2. Method of maintaining uniformity in the nature of the liquid to be applied to a travelling yarn by means of a wick, which comprises running the yarn in contact with the wick at a point along the length of the wick, and arranging the wick in the form of a siphon so as to cause the liquid which is to be applied to flow continually through the wick past the point of contact of the travelling yarn therewith.

3. Method of maintaining uniformity in the nature of a liquid to be applied to a travelling yarn by means of a wick, in which liquid said yarn is soluble, which comprises running the yarn in contact with the wick ata point along the length thereof, causing the liquid which is to be applied to flow by capillary action continually through the wick, and to and down past the point of contact of the travelling yarn therewith so as to flush the wick of any dissolved material.

4. Method of maintaining uniformity in the nature of a solvent liquid to be applied to travelling yarns by means of a wick in order to coalesce said yarn into a unitary product, which comprises running the yarn in contact with the wick at a point along the length thereof, causing the liquid which is to be applied to flow by capillary action continually through the wick, and to and down past the point of contact of the travelling yarn therewith so as to flush the wick of any dissolved material.

5. Apparatus for the application of liquid material to travelling yarns, comprising a source of supply of liquid and at least one wick adapted to present a point of contact for a travelling yarn, said wick being arranged in the form of a siphon adapted to draw the liquid to be applied continually from such source of supply and past said point of contact by siphon actio 6. Apparatus for the application of liquid material to travelling yarns, comprising a source of supply of liquid, at least one wick adapted to present a point of contact for a travelling yarn, said wick being arranged n the form of a siphon adapted to draw the liquid to be applied continually from such source of supply and past said 30 point of contact by siphon action, and means for maintaining such source of supply at constant level to ensure constant rate of flow.

7. Apparatus for the application of liquid material to travelling yarns, comprising a source of supply of liquid and a single wick adapted to present a point of contact for a travelling yarn, said wick being arranged in the form of a siphon adapted to draw the liquid to be applied continually from such source of supply and past said 40 point of contact by siphon action.

8. Method of applying a liquid at a limited rate to a travelling yarn, which comprises causing the yarn to travel to and from a point of application and drawing the liquid to be applied by capillary action at a rate in excess of that at which it is to be appliedto the yarn to and away from such point of application, whereby the liquid is applied to the yarn at the required rate, while the excess liquid is drawn away from the yarn by capillary action and fresh liquid is always presented to the yarn.

9. Method of forming aunitary product from a yarn by the application to the yarn'of a limited amount of liquid which is a solvent for the substance of the yarn, which comprises causing the yarn to travel to and from a point of application and drawing the solvent liquid at a rate in excess of that at which it is to be applied to the yarn to and away from such point of application, whereby the liquid is applied to the yarn at the required rate, while the excess liquid, together with any contamination gathered by the liquid from the substance of the yarn, is drawn away from the yarn by ,capillary action and fresh liquid 65 is always presented to the yarn.

ERNEST LESLIE GREENWOOD. 

